Sen. Stanley Rosenberg, back on Beacon Hill where he said he hopes to resume his work as a rank-and file senator after giving up the presidency in December, said Thursday he has separated from his husband Bryon Hefner, who precipitated his fall from power after being accused of sexually harassing at least four men who have business before the Legislature.

Rosenberg made his first public appearance at the State House since a tearful press conference in early December when he acknowledged the accusations against his husband and announced that Hefner would seek treatment for alcohol dependence.

"I have," Rosenberg said, when asked if had separated from his husband of one year. Asked what went into that decision, Rosenberg said, "That's personal and he is getting the treatment for alcohol that he needs and that's about all that can be said about that."

An advisor to Rosenberg said the the Amherst Democrat at this time has no plans to seek a legal divorce from Hefner. The separation was first reported Thursday by the Boston Globe.

Rosenberg returned to Beacon Hill to attend a farewell speech from Thomas McGee, who resigned his Senate in January after being sworn in as mayor of Lynn.

Several House and Senate lawmakers greeted Rosenberg enthusiastically with hugs, handshakes and pats on the back in the chamber. After a hearty handshake and hug from Speaker Robert DeLeo, the two posed for a photo on the rostrum with McGee and former Lynn lawmakers Robert Fennell and Steve Walsh.

"Very positive, friendly, exactly what I'd expect from my colleagues with whom I've served and worked for so long," Rosenberg said of the reception he received, including from the four senators who have publicly expressed interest in becoming Senate president if Rosenberg cannot return.

Rosenberg sat in the second division while Acting Senate President Harriette Chandler and Sen. Will Brownsberger presided over the ceremony, listening as McGee named him in the list of speakers and Senate presidents he'd served under in the Legislature. On his way out of the chamber afterwards, Rosenberg was intercepted several times by colleagues offering more hellos, hugs and handshakes, before leaving with an aide and Re p. Theodore Speliotis.

After an all-day private caucus that he did not attend, Rosenberg gave up the gavel to clear the way for an independent investigation into whether he broke any Senate rules in connection to the allegations against his husband, who was accused of groping and kissing four men with business before the Legislature and boasting of the sway he holds over Senate policy decisions.

Rosenberg, who promised a "firewall" between the Senate and Hefner before he assumed the presidency in 2015, has denied Hefner's influence over Senate decision-making, but declined to speculate on whether he will be able to return to the presidency at the conclusion of the Ethics Committee investigation.

"I'm looking forward to the completion of the investigation. It's underway, and I'm here representing my constituents and plan to continue to do my job," he said.

Rosenberg said he has not discussed the presidency with any of his colleagues, nor has he been reassured by any senators that they will support his return to the presidency if he is cleared by the investigation.

In fact, Rosenberg said senators have been advised to limit their interactions with him for as long as the investigation is ongoing.

"I have not discussed anything with regards to what's going to happen once the investigation is complete with my colleagues. At this point, they have been counseled that they should minimize contact with me so we can be sure, out of an abundance of caution, that nothing can be said when the investigation is over that there was any interference," he said.

The Senate Ethics Committee, chaired by Sen. Michael Rodrigues, hired the law firm Hogan Lovells to be the independent investigator in charge of the Rosenberg inquiry.

Rosenberg said he has not yet spoken with investigators, and said he could not comment on whether Hefner would speak to the lawyers leading the probe while he is seeking alcohol treatment.

Asked about his life for the past month since the allegations against Hefner were made pubic in the Boston Globe, Rosenberg said, "I've been in my district where I usually spend most of the holiday season and I'm back now along with my colleagues to do our jobs."

The Legislature has conducted little in the way of major lawmaking since mid-November.